Grinding-mill.



,g v @Zif%zd No. 856,918. PATENTED JUNE 11,1907. M. SGHRBGK.

GRINDING MILL.

AAAAAAAAAAAAAAAAA PR.28,1905.

WzL-in ass as MICHAEL SCHRECK, OF CINCINNATI, OI-IIO.

GRINDING-MILL.

Specification of Letters Patent.

Patented June 11, 1907.

Application filed April 28,1906. Serial No. 314,148.

f0 all whom it may concern:

fe Be it known that I, MIcHAEL ScHREcK, a citizentiof tliegUnitedStates, residingilatfilCincinnatigin theficounty of Hamilton and Stateof Ohio, have invented certain new and useful Improvements in Grinding-hIills'of which the following is a specification.

The object of my invention is to provide a grinding mill of improvedconstruction and operation and my invention consists in the combinationand arrangement of parts hereinafter described and claimed.

In the drawings Figure 1, is a vertical section of a grinding millembodying my invention; Fig. 2, a top plan view on a reduced scale ofthe lower or running stone; Fig. 3, a bottom plan view, on a reducedscale, of the upper or stationary stone; Fig. 4, a perspective view of aportion of the lower stone and Fig. 5, a perspective view of a portionof the upper stone.

The upper or stationary stone A is mounted in a suitable frame B and isprovided with a central opening a through which the material to beground is fed. On its bottom the stone A is provided with a grindingface a contacting with the lower or running stone C which is rotatablymounted on shaft 0. The central portionor bosom of the stone A isslightly concaved to provide a space a between it and the lower stone.At intervals the lower face of stone A is provided with grooves aradiating from opening a. These grooves have an abrupt wall a on theside from which the material to be ground is fed thereto by the actionof the lower stone. From wall a the grooves a gradually decrease indepth until they terminate flush with the surface of stone A, andgradually decrease in depth outwardly until they reaclr the grindingface after which they are of uniform depth. The portions of grooves elying in grinding face a are inclined away from the direction from whichmaterial is fed thereto and their outer ends are made narrower thantheir inner ends. The arrows on Figs. 3 and 5 indicate the direction offeed of the material between the stones.

The lower or rotatin stone C is secured upon shaft 0 by means of acentral eye or boss 0 which is conical in shape. The upper face of thestone is horizontal and is provided with curved grooves 0 having abruptwalls 0 on their carrying sides. From walls 0 these grooves graduallydecrease in depth until they terminate flush with the surface of thestone and they gradually grow shallower as they recede from the centeruntil they terminatefllat their ends flush with the inner edge of griming face 0, thus leaving the grinding face unbroken by grooves. Theshaft 0 is mounted upon a lever D by means of which it may be adjustedto carry stone O toward and away from stone A, as will be readilyunderstood by those skilled'in the art.

In operation, stone 0 is slowly rotated and material to be ground, suchas white lead mixed with oil or water, is fed to the stones throughopening a. As opening a is considerably larger than eye 0, there isample room for the material to flow off of eye a and pass to grooves cin the lower. stone. Here the curved shape'of grooves 0 tends to forcethe material outwardly while the abrupt walls 0 serve to carry thematerial. Thus it will be seen that the material will be graduallyforced outwardly to the grinding faces a and c. The spaces a between theconcave bosom of the stone A and the horizontal face of stone Cfurnishes room for the outward feed of the material and the circulationof air to keep the stones cool.

The grooves a extending over the bosom and grinding face of stone Ainsure a free feed of the material and the circulation of air, while theungrooved grinding face 0 of stone 0 insures that no material shall passthrough the stones without being thoroughly ground. By making the upperface of stone 0 horizontal, I obtain a construction in which thematerial to be ground is influenced by gravity and the grooves in thestone permitted to exert their influence thereon, unhindered. Owing tothe fact that the abrupt wall 0;" of grooves (1. is on the side fromwhich material is fed thereto by the action of stone C, the material tobe ground readily passes therefrom to the faces of the stones and theinclined outer ends of the grooves tend to facilitate the feed and drawair between the grinding faces to cool the stones. By making the outerends of the portions (L5 of grooves a? narrower than the inner ends, toorapid discharge of the ground material is prevented.

This machine is especially adapted to the grinding of paints, whitelead, starch or any substance of a liquid nature or mixed with a liquid.

The upper stone may be rotated if desired and the lower stone remainstationary.

While I have illustrated and described the preferred construction .forcarrying my invention into effect, this is capable of modificationWithout departing from the spirit of the invention. I therefore do notwish to be limited to the exact construction shown in the drawings, but

What I claim as new and desire to secure by Letters Patent is 1. In agrinding mill, the combination of: a stationary stone having a centralopening and a concaved bosom, said stone having grooves therein theouter ends of which are inclined-and narrower than at their inner end,and a rotatable-stone having a horizontal upper face provided-withcurved grooves.

2. In combination with an upper stationary stone having a centralopening and concaved bosom, with radial grooves therein the outer endsof whichgrooves are inclined and narrower at their outer than at theirinner ends, a rotatable stone having a plain grinding face and curvedfeed grooves, said feed grooves decreasing in depth until they mergeinto said grinding face.

3. In a grinding mill an upper stone having'a central opening and aseries of radial grooves having their outer ends angularly disposed andof less width than the remainder of said grooves, and a lower stonehaving a grinding face and a conical boss-extending in said opening ofthe upper stone and curved feed grooves leading from said boss'out-Wardly and-terminating at the grinding face of said lower stone.

M. 'SOHRECK.

Witnesses:

-BRAYTON GJRICHARDS,

M. J. GALLAGH-AR.

